/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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package org.hisp.dhis.program.variable;

import org.hisp.dhis.parser.expression.CommonExpressionVisitor;
import org.hisp.dhis.parser.expression.ProgramExpressionParams;
import org.hisp.dhis.program.AnalyticsType;

/**
 * Program indicator variable: event date (also used for execution date)
 *
 * @author Dusan Bernat
 */
public class vScheduledDate extends ProgramDateVariable {

  private static final String PLACEHOLDER_FORMAT =
      "FUNC_CTE_VAR( type='vScheduledDate', column='scheduleddate', piUid='%s', psUid='null', offset='0')";

  @Override
  public Object getSql(CommonExpressionVisitor visitor) {
    if (!visitor.isUseExperimentalSqlEngine()) {
      return getSqlLegacy(visitor);
    }
    ProgramExpressionParams params = visitor.getProgParams();

    if (params != null
        && params.getProgramIndicator() != null
        && AnalyticsType.ENROLLMENT == params.getProgramIndicator().getAnalyticsType()) {
      String piUid = params.getProgramIndicator().getUid();
      return String.format(PLACEHOLDER_FORMAT, piUid);
    } else {
      // For Event analytics or other contexts, return the direct column name
      return "scheduleddate";
    }
  }

  public Object getSqlLegacy(CommonExpressionVisitor visitor) {

    ProgramExpressionParams params = visitor.getProgParams();

    if (AnalyticsType.ENROLLMENT == params.getProgramIndicator().getAnalyticsType()) {
      String sqlStatement =
          visitor
              .getStatementBuilder()
              .getProgramIndicatorEventColumnSql(
                  null,
                  "scheduleddate",
                  params.getReportingStartDate(),
                  params.getReportingEndDate(),
                  params.getProgramIndicator());

      return maybeAppendEventStatusFilterIntoWhere(sqlStatement);
    }

    return "scheduleddate";
  }

  private String maybeAppendEventStatusFilterIntoWhere(String sqlStatement) {
    int index = sqlStatement.indexOf("order by occurreddate");

    if (index == -1) {
      return sqlStatement;
    }

    return sqlStatement.substring(0, index)
        + " and eventstatus = 'SCHEDULE' "
        + sqlStatement.substring(index);
  }
}
